18 Wisconsin Academy of Sciences, Arts, and Letters. 



June and included both hard and soft wood trees. It was found 

 that all starch disappeared in winter from Populus deltoides, 

 Salix alba and Juniperus virgindana, while Quercus rubra, JJlmus 

 americana, Acer saccharum and Juglans nigra retained consid- 

 erable starch in the wood through the winter. TiLia americana 

 underwent a starch reduction but retained some in the phloem, 

 medullary rays, and xylem, while Carya glabra lost its starch 

 in small stems but retained about a fourth of it in larger stems. 



None of these trees except Carya showed a reduction of starch 

 in the roots during winter. Large amounts of sugar were found 

 present only in spring as the buds were unfolding. The trees 

 tested had a maximum fat content in late fall and a minimum in 

 spring. These tests seem to show that broad-leaved hard wood 

 trees cannot be called starch trees nor those with soft wood fat 

 trees, as had been done by Fischer. 



Niklewski 31 concluded from his study that the starch conver- 

 sion in soft wood trees like Tilia, Betula, etc. is practically com- 

 plete on the approach of winter, while in hardwood trees like 

 Prunus and Syringa it is only partial. It was found that fats 

 are more abundant in winter and also that a rise in temperature 

 increased the amount. 



According to Wotczal 32 starch transformation begins in spring 

 in the distal parts of shoots and roots and proceeds towards the 

 older portions of the tree, although it starts later in roots than 

 in the shoots. But normally these two waves of starch trans- 

 formation starting in the roots and shoots do not encounter one 

 another, and in this way a starch residue remains in the older 

 wood and in the region of the root-crown. The deposition of 

 starch then occurs in the reverse manner throughout the tree, 

 i. e. it begins in the oldest parts and around the root-erown and 

 proceeds wave-like toward the distal ends of the shoots and roots. 



The work by Fabricius reviewed above shows that remarkable 

 and apparently wave-like progressive changes occur in the state 

 and distribution of reserve foods in trees and that maxima and 

 minima of the different types occur in certain parts at rather 

 definite periods of the seasonal history. The above cited experi- 



S1 Niklewski, B. Untersuchungen fiber die Umwandlung einiger 

 stickstoffreier Reservestoffe wahrend der Winterperiode der Baume 

 Beihefte Bot. Centralbl. 19 Abt 1:68-117. 1906. 



"Wotczal, E. Die Starkeablagerung in den Holzgewachsen Bot 

 Centralbl. 41:99-100. 1890. 



